1. Field of the Invention
The invention relates to a seat belt retractor, and more particularly to a seat belt retractor that has a detection device to detect whether a webbing body of the seat belt is pulled out or not.
2. Description of Related Art
Every occupant in a vehicle is required to fasten a seat belt for safety. The conventional seat belt has a buckle assembly, a webbing body, a tongue, and a detection device. The tongue is mounted on the webbing body and is selectively locked into the buckle assembly. The detection device is mounted on the buckle assembly to detect whether the tongue is locked or not. If the tongue is not locked into the buckle assembly, the detection device sends a signal to a controller of the vehicle, and then a light or a sound generated by the vehicle reminds the occupants in the vehicle to fasten the seat belt.
Some drivers and passengers, as a matter of convenience, use an auxiliary tongue for inserting into the buckle assembly. Though the drivers and passengers do not actually fasten the seat belts, the detection device does not send the signal to the controller of the vehicle. Therefore, the reminding function of the detection device mounted on the buckle assembly is not effectively performed.
To overcome the shortcomings, the present invention provides a seat belt retractor having a detection device to obviate the aforementioned problems.